Fracturing flow-back fluid recovery pipe for oil exploitation

Abstract

The invention belongs to the technical field of oil exploitation, and relates to a fracturing flow-back fluid recovery pipe for oil exploitation, which comprises a tubular main body, the top surface of the main body is provided with a permeation hole, the bottom surface of the inner wall of the main body is fixedly connected with an elastic connecting sheet, and a gap between the connecting sheet and the inner wall forms a first cavity; a hollow fixing block is communicated in the first cavity, the inner wall of the fixing block is hermetically and slidably connected with a sliding plate, the bottom end of the sliding plate is connected with a spring, the spring is fixedly connected with a pressure sensor, and the other end of the pressure sensor is connected with the bottom surface of the fixing block; air holes are formed in the side wall of the bottom end of the fixing block. Compared with the prior art, according to the recovery pipe, flow-back liquid flows to the connecting piece, the pressure of the flow-back liquid is converted into gas pressure, then the gas pressure is transmitted to the pressure sensor for centralized detection, the capacity of the fracturing flow-back liquid is judged according to the pressure detected by the pressure sensor, kinetic energy of an oil well pump is adjusted according to the capacity of the flow-back liquid, and the recovery rate of the fracturing flow-back liquid is improved. The service life of the oil well pump is prolonged, and energy waste is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oil exploitation, in particular to a fracturing return fluid recovery pipe for oil exploitation. Background Art

[0002] In the field of oil, fracturing refers to a method of using hydraulic force to create cracks in oil and gas layers during oil or gas production, also known as hydraulic fracturing. Fracturing is to artificially create cracks in the formation to improve the flow environment of oil underground and increase the output of oil wells. It plays an important role in improving the flow conditions at the bottom of the oil well and improving the utilization of the oil layer. Before oil fracturing, it is necessary to lay pre-buried pipelines in the formation and use a pump to collect the return fluid produced by the first fracturing to determine what kind of extraction method is suitable for the oil in the formation. If the oil is thin, a screw pump can be used for oil production. If the oil is thick, in order to avoid oil clogging the screw tooth groove, a rodless pump with high energy consumption is usually used for oil production.

[0003] With regard to the existing related technologies, the inventors believe that the following defects often exist: due to the complex oil deposition conditions inside the formation, the return fluid capacity in the pipeline under different working conditions will be different. If the capacity of the fracturing return fluid in the pipeline cannot be judged, the kinetic energy of the oil pump cannot be adjusted. When the return fluid capacity in the pipeline is small, the oil pump will consume a large amount of kinetic energy when working, which will damage the service life of the oil pump and waste energy. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention provides a fracturing flowback fluid recovery pipe for oil production to solve at least one technical problem raised in the background technology.

[0005] The fracturing return fluid recovery pipe for oil production provided by the present invention is used for recovering fracturing return fluid in oil production. By making the return fluid fall uniformly on a connecting piece, the pressure of the return fluid is converted into gas pressure and then transmitted to a pressure sensor for centralized detection. The pressure detected by the pressure sensor can be used to determine the capacity of the fracturing return fluid in the recovery pipe, so that the kinetic energy of the oil pump can be adjusted according to the capacity of the fracturing return fluid in the recovery pipe, so as to achieve the effect of increasing the service life of the oil pump and reducing energy waste.

[0006] The invention discloses a fracturing flowback fluid recovery pipe for petroleum exploitation, comprising a tubular main body, a top surface of the main body being provided with a plurality of penetration holes, a connecting piece being fixedly connected to the bottom surface of the inner wall of the main body, the connecting piece being made of elastic material, a first cavity being formed by a gap between the connecting piece and the bottom surface of the inner wall of the main body, a hollow fixed block being connected in communication with the first cavity, a slide plate being sealingly and slidingly connected to the inner wall of the fixed block, a spring being fixedly connected to the bottom end of the slide plate, a pressure sensor being fixedly connected to one end of the spring away from the slide plate, the pressure sensor being fixedly connected to the bottom surface of the fixed block at one end away from the spring, an air vent being provided on the bottom side wall of the fixed block. By preburying the recovery pipe horizontally in the formation and leaving the permeable holes upward, when the fracturing return fluid is recovered, the fracturing return fluid will first penetrate the formation and then penetrate into the recovery pipe from the permeable holes. At this time, the return fluid will flow to the rubber connecting piece. As the return fluid volume continues to increase, the connecting piece will deform under the pressure of the return fluid and squeeze the gas in the first cavity, thereby increasing the air pressure in the first cavity. The gas in the first cavity pushes the slide plate to slide downward, and the slide plate will squeeze the spring when sliding downward, and the pressure will be transmitted to the pressure sensor through the spring. Since the existing return fluid recovery pipe is long and the collected return fluid is unevenly distributed, it is often necessary to set up multiple sets of sensors to detect the return fluid at different positions. The return fluid can be uniformly dropped on the connecting piece by the recovery pipe of the present invention, and the pressure of the return fluid is converted into gas pressure and then transmitted to the pressure sensor for centralized detection. Compared with the existing measurement method, it is simpler, faster and more accurate. The pressure detected by the pressure sensor can be received by an external display. The volume of the fracturing return fluid in the recovery pipe can be judged by the pressure value detected by the pressure sensor. Then, the kinetic energy of the oil pump can be adjusted according to the volume of the return fluid, so as to improve the service life of the oil pump and reduce the waste of energy. The return fluid recovered by multiple recovery pipes can be collected in a well platform, which can be composed of four wells, which can be numbered as A, B, C and D. After entering the well platform, the return fluid will enter wells A, B, C and D, and then wells A and B will be fractured first, and then wells C and D will be fractured, so that the return fluid can be directly recovered and processed on site without being transported to a specific location for processing, simplifying the processing process.

[0007] Preferably, a sponge block is fixedly connected to the infiltration hole. When the infiltration hole is a circular hole, the sponge block is preferably a circular sponge block. With the help of the sponge block (the density of the sponge block is set relatively sparsely to facilitate the flow of return fluid inside it), impurities in the formation can be filtered to prevent impurities from entering the recovery pipe. At the same time, during the process of the return fluid infiltrating from the sponge block into the recovery pipe, the sponge block can also filter out impurities in the return fluid.

[0008] Preferably, a guide column is provided below the sponge block; by virtue of the fit between the guide column and the sponge block, or by setting the diameter of the guide column to be larger than the inner diameter of the infiltration hole (the top of the guide column will partially contact the inner wall of the recovery tube below the infiltration hole, and since the tube wall of the recovery tube is arc-shaped, the guide column will not block the infiltration hole), the return liquid that permeates out of the sponge block can be vertically guided to drip into the recovery tube, thereby preventing the return liquid from remaining on the inner wall of the recovery tube and affecting the pressure sensor's detection result of the return liquid capacity in the recovery tube.

[0009] Preferably, the inner wall of the main body is fixedly connected with a telescopic mechanism, and a connecting block is fixedly connected to the telescopic mechanism, and the connecting block can be preferably a trapezoidal connecting block; the telescopic mechanism is used to drive the connecting block to rise and fall; the bottom end of the guide column is fixedly connected to the connecting block, and the top end of the guide column can extend into the penetration hole and squeeze the sponge block; the top end of the sponge block is provided with a partition, and when the penetration hole is a circular hole, the partition is preferably a circular partition; the partition is fixedly connected to the inner wall of the penetration hole, and a plurality of filter holes are provided on the partition. By using the filter holes on the partition, the soil in the stratum can be prevented from blocking the top end of the sponge block, avoiding the situation that the return fluid is not easy to penetrate into the sponge block due to the blockage of the sponge block, thereby improving the penetration effect of the return fluid in the sponge block. By starting the telescopic mechanism, the telescopic mechanism pushes the connecting block, and the diameter of the guide column is smaller than the inner diameter of the permeation hole, so that the guide column can extend into the permeation hole under the push of the telescopic mechanism. At this time, the connecting block will drive the guide column to squeeze the sponge block, so that the return liquid in the sponge block is squeezed onto the trapezoidal connecting block, and then flows from the inclined sides of the connecting block to the recovery pipe, and then flows to the connecting piece, thereby improving the sponge block The efficiency of conveying the return liquid, while preventing the situation where more return liquid remains in the sponge block and affects the capacity of the return liquid in the recovery pipe, thereby affecting the measurement result of the pressure sensor. Preferably, the sponge block is embedded with a hollow elastic block, and a plurality of air outlets are opened on the elastic block, and the elastic block is made of an elastic material (such as rubber). When the guide column squeezes the sponge block, it also squeezes the elastic block. At this time, the elastic block will first deform and expand to squeeze the inside of the sponge block, thereby further squeezing out the return liquid in the sponge block, and then when the sponge block is continuously squeezed, the elastic block will shrink, so that the gas in the elastic block is blown out from the air outlet. Air holes can be set on the side, top and bottom surfaces of the elastic block. At this time, the blown gas can be blown onto the guide column and the connecting block, thereby blowing away the residual return liquid on the guide column and the connecting block. At the same time, the gas can also be blown to the top of the sponge block to dredge the top of the sponge block, further reducing the blockage of the sponge block.

[0010] Preferably, a connecting wire is fixedly connected to the bottom end of the connecting block, and an end of the connecting wire away from the connecting block is fixedly connected to a connecting piece; when there is return fluid on the connecting piece, the connecting piece will bend and deform downward, and at this time, when the oil pump extracts the return fluid in the recovery pipe, part of the return fluid cannot be easily extracted because the position of the return fluid in the recovery pipe is relatively low. At this time, the telescopic mechanism can push the connecting block to move upward, so that the connecting block pulls the connecting wire upward. At this time, the connecting wire will pull the connecting piece upward, causing the connecting piece to bend slightly upward, thereby raising the position of the return fluid, thereby allowing the oil pump to extract the return fluid in the recovery pipe more conveniently.

[0011] Preferably, the telescopic mechanism is an electric telescopic rod, the top end of which is fixedly connected to the connecting block; or, the telescopic mechanism is a cylinder, the piston rod of which is fixedly connected to the connecting block.

[0012] Preferably, a pointed cone is fixedly connected to the top of the sponge block at a position corresponding to the filter hole, a group of annular evenly distributed hook-shaped hollow blocks are fixedly connected to the surface of the pointed cone, the end of the hollow block away from the pointed cone is a free end, the hollow block is made of elastic material, and a limiting rod is fixedly connected to the inner wall of the filter hole, and the limiting rod is used to limit the upward movement of the free end of the hollow block. The hollow block is made of rubber. When the sponge block is squeezed and pushed, the pointed cone will also be pushed upward to push away the soil accumulated on the filter hole for dredging. At the same time, the hollow block will also move upward with the pointed cone. During the upward movement of the hollow block, the free end will be limited by the limit rod to prevent the free end from continuing to move upward. Then the hollow block will be elongated and deformed in the subsequent rising process, and will be squeezed and expanded by the soil above the filter hole, so that the adjacent hollow blocks will expand to fit each other and form a seamless and complete conical surface, thereby pushing the soil in the filter hole out and to the top side of the filter hole, thereby effectively dredging the filter hole and preventing the filter hole from being blocked and affecting the return fluid from entering the recovery pipe.

[0013] Preferably, a connecting port is provided at one end of the main body, and a connecting head is provided at the other end; an annular sealing sleeve is fixedly connected to the inner wall of the main body near the connecting port, and a gap is provided between the sealing sleeve and the inner wall of the main body; the sealing sleeve is fixedly connected to a connecting piece on one side near the fixed block, and an annular spacer is fixedly connected between the sealing sleeve and the inner wall of the main body, and the sealing sleeve and the spacer are made of elastic material (such as rubber); glue is stored in the gap, a liquid outlet groove penetrating the sealing sleeve is provided on the surface of the sealing sleeve, a connecting membrane is fixedly connected to the inner wall of the liquid outlet groove, and a crushing mechanism is provided on the sealing sleeve, and the crushing mechanism includes a chamfer provided on the inner wall of the sealing sleeve. When multiple recovery pipes are connected, when the connector of one of the recovery pipes enters the connection port of another recovery pipe, the sealing sleeve will fit against the connector and squeeze the chamfer, causing the sealing sleeve made of rubber material to deform. At this time, the gap between the sealing sleeve and the recovery pipe will become smaller, so that the glue in the gap will break the connecting membrane, thereby achieving the effect of automatically allowing the glue to flow out. At this time, the glue will flow to the connecting part between the connector and the recovery pipe, thereby improving the sealing effect of the connecting part between the connector and the recovery pipe.

[0014] Preferably, an annular elastic membrane is fixedly connected between the side of the spacer away from the connecting piece and the inner wall of the main body, and glue is filled in the cavity between the elastic membrane and the sealing sleeve; when the connecting membrane is damaged, the elastic membrane in the original bulging state will push the glue in the gap, so that the glue is squeezed and fully filled in the connection between the connecting head and the recovery pipe, thereby achieving the effect of further improving the sealing of the recovery pipe and the connecting head.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. The return fluid flows to the connecting piece. As the capacity continues to increase, the connecting piece will deform under pressure to squeeze the gas in the first cavity, so that the gas in the first cavity pushes the slide plate. At this time, the slide plate will squeeze the spring, so that the spring transmits the pressure to the pressure sensor. The pressure value detected by the pressure sensor can be received through an external display. The capacity of the fracturing return fluid in the recovery pipe can be judged by the pressure value detected by the pressure sensor. The kinetic energy of the oil pump can then be adjusted according to the capacity of the return fluid, thereby increasing the service life of the oil pump and reducing energy waste.

[0017] 2. With the help of sponge blocks (the density of the sponge blocks is set relatively sparsely to facilitate the flowback fluid to flow inside them), impurities in the formation can be filtered to prevent impurities from entering the recovery pipe. At the same time, when the flowback fluid penetrates from the sponge block into the recovery pipe, the sponge block can also filter out impurities in the flowback fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the accompanying drawings.

[0019] Figure 1 It is a schematic diagram of the structure of the fracturing flowback fluid used in petroleum mining of the present invention;

[0020] Figure 2 is a cross-sectional view of the recovery pipe in the present invention;

[0021] Figure 3 yes Figure 2 A magnified image of point A;

[0022] Figure 4 It is a partial structural schematic diagram of the recovery pipe in the present invention;

[0023] Figure 5 is a cross-sectional view of a sponge block and a partition in the present invention;

[0024] Figure 6 yes Figure 5 The enlarged view of point B in the middle;

[0025] Figure 7 It is a top view of the pointed cone in the present invention.

[0026] Reference numerals:

[0027] 1. Main body; 2. Connector; 3. Connecting piece; 4. First cavity; 5. Fixed block; 6. Slide plate; 7. Spring; 8. Pressure sensor; 9. Sponge block; 10. Guide column; 11. Connecting block; 12. Electric telescopic rod; 13. Partition; 14. Filter hole; 15. Elastic block; 16. Penetration hole; 17. Connecting line; 18. Sealing sleeve; 19. Partition; 20. Liquid outlet trough; 21. Connecting membrane; 22. Elastic membrane; 23. Cone; 24. Hollow block; 25. Limit rod; 26. Chamfer. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0029] like Figures 1 to 4 As shown, the present invention provides a fracturing return fluid recovery pipe for petroleum mining (hereinafter referred to as the recovery pipe), the recovery pipe includes a tubular main body 1, a plurality of penetration holes 16 are opened on the top surface of the main body 1, the penetration holes 16 penetrate the wall surface of the main body 1 to connect the inner and outer spaces of the main body 1, so that the fracturing return fluid can penetrate into the recovery pipe from the penetration holes 16.

[0030] The two ends of the bottom surface of the inner wall of the main body 1 are fixedly connected with arc-shaped connecting pieces 3, and the connecting pieces 3 are made of elastic material (such as rubber). The gap between the connecting piece 3 and the recovery pipe main body 1 forms a first cavity 4. A hollow fixed block 5 is fixedly connected to the bottom of the main body 1, and the internal cavity of the fixed block 5 is connected to the first cavity 4. The inner wall of the cavity inside the fixed block 5 is slidably connected with a slide plate 6, and the inner wall of the cavity inside the fixed block 5 is sealed with the slide plate 6. The slide plate 6 divides the cavity inside the fixed block 5 into two, the cavity on the upper part of the slide plate 6 is connected to the first cavity 4, and the cavity on the lower part of the slide plate 6 is completely isolated from the first cavity 4. The bottom end of the slide plate 6 is fixedly connected with a spring 7, and the end of the spring 7 away from the slide plate 6 is fixedly connected with a pressure sensor 8. The end of the pressure sensor 8 away from the spring 7 is fixedly connected to the bottom surface of the fixed block 5, and the bottom side wall of the fixed block 5 is provided with an air vent, and the cavity at the bottom of the slide plate 6 is connected to the outside through the air vent.

[0031] By pre-burying the recovery pipe horizontally in the formation and letting the permeable hole 16 face upward, when the fracturing return fluid is recovered, the fracturing return fluid will first penetrate the formation, and then penetrate into the recovery pipe from the permeable hole 16. At this time, the return fluid will flow to the connecting piece 3. As the amount of return fluid in the recovery pipe continues to increase, the connecting piece 3 will deform under the pressure of the return fluid to squeeze the gas in the first cavity 4, so that the air pressure in the first cavity 4 increases, and the gas in the first cavity 4 pushes the slide plate 6 to slide downward; when the slide plate 6 slides downward, it will squeeze the spring 7, and the pressure will be transmitted to the pressure sensor 8 through the spring 7. Since the existing return fluid recovery pipe is long and the collected return fluid is unevenly distributed, it is often necessary to set up multiple sets of sensors to detect the return fluid at different positions. The recovery pipe of the present invention makes the return fluid fall uniformly on the connecting piece 3, converts the pressure of the return fluid into gas pressure, and then transmits it to the pressure sensor 8 for centralized detection. This measurement method is simple, fast and accurate. The pressure detected by the pressure sensor 8 can be received and displayed by an external display. The amount of fracturing flowback fluid in the recovery pipe is determined by the pressure detected by the pressure sensor 8. The greater the pressure, the greater the amount of fracturing flowback fluid in the recovery pipe. The kinetic energy of the oil pump can be adjusted according to the amount of fracturing flowback fluid in the recovery pipe to increase the service life of the oil pump and reduce energy waste.

[0032] The return fluid recovered by the recovery pipe can be collected in a well platform. In one embodiment, the well platform can be composed of four wells, which can be numbered A, B, C and D. After entering the well platform, the return fluid will enter wells A, B, C and D. Then, wells A and B will be fractured first, and then wells C and D will be fractured, so that the return fluid can be directly recovered and processed on site without having to be transported to a specific location for treatment, thereby simplifying the treatment process.

[0033] In some embodiments, see Figure 3A circular sponge block 9 is fixedly connected in the permeation hole 16. The sponge block 9 can filter impurities in the formation to prevent the impurities from entering the recovery pipe; at the same time, when the return fluid penetrates from the sponge block 9 into the recovery pipe, the sponge block 9 can also filter out impurities in the return fluid.

[0034] The density of the sponge block 9 is preferably set to be relatively sparse to facilitate the flow of the return fluid inside the sponge block 9 .

[0035] When the backflow liquid flows from the inner wall of the recovery pipe body 1 to the connecting piece 3, part of the backflow liquid will remain on the inner wall of the recovery pipe, thereby affecting the detection result of the backflow liquid capacity in the recovery pipe by the pressure sensor 8. In order to prevent the backflow liquid from flowing from the inner wall of the recovery pipe to the connecting piece 3, a guide column 10 can be provided below the sponge block 9, and the guide column 10 is used to guide the backflow liquid that permeates the sponge block 9 to drip vertically onto the connecting piece 3 in the recovery pipe.

[0036] In some embodiments, see Figure 3 A guide column 10 is provided at the bottom end of the sponge block 9, and the top of the guide column 10 fits the bottom of the sponge. By virtue of the fit between the guide column 10 and the sponge block 9, the return liquid seeping out of the sponge block 9 will flow directly onto the guide column 10, and then drip onto the connecting piece 3 in the recovery pipe through the vertical diversion of the guide column 10.

[0037] In some other embodiments, the diameter of the guide column 10 is larger than the inner diameter of the permeation hole 16. Since the wall of the recovery pipe is arc-shaped, the top of the guide column 10 will partially contact the inner wall of the recovery pipe below the permeation hole 16 without blocking the permeation hole 16. The guide column 10 blocks the path of the return fluid from the permeation hole 16 to the inner wall of the recovery pipe. The return fluid that flows to the inner wall of the recovery pipe contacts the guide column 10 and flows to the guide column 10, and then drips down along the guide column 10 to the connecting piece 3 in the recovery pipe. By providing the guide column 10, the return fluid is effectively prevented from flowing along the inner wall of the recovery pipe to the connecting piece 3, and the residue of the return fluid on the inner wall of the recovery pipe is reduced, thereby improving the accuracy of the pressure sensor 8 in detecting the return fluid volume in the recovery pipe.

[0038] In some embodiments, see Figure 4 A circular partition 13 is provided at the top of the sponge block 9, and the partition 13 is fixedly connected to the inner wall of the penetration hole 16, and a plurality of filter holes 14 are evenly opened on the partition 13; by using the filter holes 14 on the partition 13, the soil in the formation can be prevented from blocking the top of the sponge block 9, thereby improving the penetration effect of the return fluid in the sponge block 9.

[0039] In some embodiments, see Figure 2 and Figure 4The inner wall of the recovery pipe is fixedly connected to an electric telescopic rod 12 through a bracket, and the top of the electric telescopic rod 12 is fixedly connected to a connecting block 11. The connecting block 11 is preferably a trapezoidal connecting block 11, and its bottom surface area is larger than the top surface area, which is conducive to the liquid on the top of the connecting block 11 to flow down quickly along the inclined sides of the connecting block 11. The bottom end of the guide column 10 is fixedly connected to the connecting block 11, and the diameter of the guide column 10 is smaller than the inner diameter of the penetration hole 16, so that the guide column 10 can be pushed into the penetration hole 16 by the electric telescopic rod 12. By starting the electric telescopic rod 12, the electric telescopic rod 12 extends to push the connecting block 11. At this time, the connecting block 11 will drive the guide column 10 to extend into the infiltration hole 16 to squeeze the sponge block 9, so that the return liquid in the sponge block 9 is squeezed out; the return liquid squeezed out of the sponge block 9 flows along the guide column 10 to the trapezoidal connecting block 11, and then quickly flows from the inclined sides of the connecting block 11 to the connecting piece 3 in the recovery pipe, which can effectively improve the sponge block 9 The efficiency of conveying the return liquid, while preventing the amount of return liquid in the recovery pipe from being affected by a large amount of return liquid remaining in the sponge block 9, thereby affecting the accuracy of the measurement result of the pressure sensor 8. When the electric telescopic rod 12 retracts, it pulls the connecting block 11. At this time, the connecting block 11 will drive the guide column 10 to retract from the infiltration hole 16 and stop squeezing the sponge block 9.

[0040] In some embodiments, see Figures 5 to 7 The top of the sponge block 9 is fixedly connected with a plurality of pointed cones 23, and the positions and numbers of the pointed cones 23 correspond to the filter holes 14. A group of evenly arranged annular hook-shaped hollow blocks 24 are fixedly connected to the surface of the pointed cone 23, and one end of the hollow block 24 fixed on the pointed cone 23 is the fixed end of the hollow block 24, and the end of the hollow block 24 away from the pointed cone 23 is the free end of the hollow block 24. The hollow block 24 is made of elastic material; preferably, the hollow block 24 is made of rubber. The inner wall of the filter hole 14 is fixedly connected with a limit rod 25 arranged to be inclined downward. When the sponge block 9 is squeezed and pushed upward, the pointed cone 23 will also be pushed to move upward, pushing away the soil accumulated on the filter hole 14 for dredging; at the same time, the hollow block 24 will also move upward with the pointed cone 23. During the upward movement of the hollow block 24, the free end will be blocked by the limit rod 25, limiting the free end from continuing to move upward, and then the hollow block 24 will be elongated and deformed during the subsequent rising process, and at the same time will be squeezed and expanded by the soil above the filter hole 14, so that the adjacent hollow blocks 24 expand to fit each other, and the gaps between the hollow blocks 24 gradually become smaller until a seamless and complete conical surface is formed, thereby pushing the soil in the filter hole 14 out and toward the top side of the filter hole 14, thereby effectively dredging the filter hole 14 and preventing the filter hole 14 from being blocked and affecting the return fluid from entering the recovery pipe.

[0041] In some embodiments, a hollow elastic block 15 is embedded in the sponge block 9. The elastic block 15 is made of an elastic material (such as rubber), and air vents are evenly arranged around the elastic block 15. When the guide column 10 squeezes the sponge block 9, the elastic block 15 is also squeezed. At this time, the elastic block 15 will first deform and expand to squeeze the inside of the sponge block 9, thereby further squeezing out the return fluid in the sponge block 9. When the sponge block 9 is continuously squeezed, the gas in the elastic block 15 is blown out from the air vents, causing the elastic block 15 to shrink. The gas blown out from the air outlet on the side of the elastic block 15 can be blown onto the inner wall of the penetration hole 16. The airflow changes direction after hitting the inner wall. The gas after changing direction can be blown onto the guide column 10 and the connecting block 11, thereby blowing away the residual backflow liquid on the guide column 10 and the connecting block 11; the gas blown out from the air outlet at the bottom of the elastic block 15 can be directly blown onto the guide column 10 and the connecting block 11, thereby blowing away the residual backflow liquid on the guide column 10 and the connecting block 11; at the same time, the gas blown out from the air outlet on the top of the elastic block 15 can also be blown to the top of the sponge block 9 to dredge the top of the sponge block 9, thereby further reducing the blockage of the sponge block 9.

[0042] In some embodiments, a connection port is provided at one end of the main body 1 of the recovery tube, and a connector 2 is provided at the other end. When multiple recovery tubes are connected, the connector 2 of one recovery tube is inserted into the connection port of another recovery tube.

[0043] See also Figure 2 and Figure 3 An annular sealing sleeve 18 is fixedly connected to the end of the inner wall of the recovery pipe away from the connector (i.e., the end close to the connection port), and there is a gap between the sealing sleeve 18 and the inner wall of the recovery pipe. The side of the sealing sleeve 18 close to the fixed block 5 is fixedly connected to the connecting piece 3, and an annular spacer 19 is fixedly connected between the sealing sleeve 18 and the inner wall of the recovery pipe. A fluid adhesive, such as glue, is stored between the sealing sleeve 18 and the inner wall of the recovery pipe. One or more liquid outlet grooves 20 are evenly opened on the surface of the sealing sleeve 18, and a connecting membrane 21 is fixedly connected to the inner wall of the liquid outlet groove 20.

[0044] The sealing sleeve 18 is provided with a crushing mechanism, which includes a chamfer 26 provided on the inner wall of the sealing sleeve 18. The sealing sleeve 18 and the spacer 19 are made of rubber material. When the connector 2 of one recovery pipe is inserted into the connection port of another recovery pipe, the sealing sleeve 18 will fit with the connector 2, and the connector 2 will squeeze the chamfer 26, so that the sealing sleeve 18 made of rubber material is deformed. At this time, the gap between the sealing sleeve 18 and the recovery pipe will become smaller, so that the glue in the gap will crush the connecting film 21 in the liquid outlet groove 20, and the glue stored between the sealing sleeve 18 and the inner wall of the recovery pipe will automatically flow out of the liquid outlet groove 20, and the outflowing glue will flow to the connection part of the connector 2 and the recovery pipe, and the connector 2 and the inner wall of the recovery pipe will be bonded and sealed, thereby improving the sealing effect of the connection part of the connector 2 and the recovery pipe.

[0045] In some embodiments, see Figure 3 An annular elastic membrane 22 is fixedly connected between the side of the spacer 19 away from the connecting piece 3 and the inner wall of the recovery pipe, and glue can be filled in the cavity between the elastic membrane 22 and the sealing sleeve 18; when the connecting membrane 21 is damaged, the elastic membrane 22 in the original bulging state will push the glue in the cavity, so that the glue is squeezed and fully filled in the connection between the connection and the recovery pipe, thereby achieving the effect of further improving the sealing of the recovery pipe and the connector 2.

[0046] When the recovery pipe of the present invention is used to recover and process the fracturing return fluid in oil production, the recovery pipe is pre-buried horizontally in the formation, and the permeable hole 16 is upward; then when the fracturing return fluid is recovered, the fracturing return fluid will first penetrate the formation, and then penetrate into the recovery pipe from the permeable hole 16, and the return fluid in the recovery pipe will be collected on the connecting piece 3. As the fracturing return fluid in the recovery pipe continues to increase, the pressure of the return fluid on the connecting piece 3 gradually increases, and the connecting piece 3 is deformed under the pressure of the return fluid and squeezes the gas in the first cavity 4,

[0047] The gas pressure in the first cavity 4 increases, and the gas in the first cavity 4 pushes the slide plate 6 to slide downward; when the slide plate 6 slides downward, it squeezes the spring 7, and the pressure is transmitted to the pressure sensor 8 through the spring 7. Since the existing backflow liquid recovery pipe is long and the collected backflow liquid is unevenly distributed, it is often necessary to set up multiple sets of sensors to detect the backflow liquid at different positions. The recovery pipe of the present invention makes the backflow liquid fall uniformly on the connecting piece 3, converts the pressure of the backflow liquid into gas pressure, and then transmits it to the pressure sensor 8 for centralized detection. The measurement method is simpler, faster and more accurate.

[0048] The pressure detected by the pressure sensor 8 can be received and displayed by an external display. The amount of fracturing return fluid in the recovery pipe can be determined by the pressure detected by the pressure sensor 8. The greater the pressure, the greater the amount of fracturing return fluid in the recovery pipe. The kinetic energy of the oil pump can be adjusted according to the amount of fracturing return fluid in the recovery pipe to increase the service life of the oil pump and reduce energy waste.

[0049] The return fluid recovered by the recovery pipe can be collected in a well platform. The well platform can be composed of four wells, which can be numbered A, B, C and D. After entering the well platform, the return fluid will enter wells A, B, C and D. Then, wells A and B will be fractured first, and then wells C and D will be fractured, so as to directly recover and treat the return fluid on site without having to transport it to a specific location for treatment.

[0050] By using the sponge block 9, impurities in the formation can be filtered to prevent the impurities from entering the recovery pipe. At the same time, when the return fluid penetrates from the sponge block 9 into the recovery pipe, the sponge block 9 can also filter out impurities in the return fluid.

[0051] By using the guide column 10, the return liquid that permeates from the sponge block 9 can be vertically guided to drip into the recovery pipe, preventing the return liquid from flowing from the inner wall of the recovery pipe to the connecting piece 3. Some return liquid will remain on the inner wall of the recovery pipe, thereby affecting the detection result of the pressure sensor 8 on the return liquid capacity in the recovery pipe.

[0052] By using the filter holes 14 on the partition 13, the soil in the stratum can be prevented from blocking the top of the sponge block 9, thereby improving the penetration effect of the return fluid in the sponge block 9.

[0053] By starting the electric telescopic rod 12, the electric telescopic rod 12 pushes the connecting block 11. At this time, the connecting block 11 will drive the guide column 10 to squeeze the sponge block 9 (at this time, the diameter of the guide column 10 is smaller than the inner diameter of the permeation hole 16), thereby squeezing the return fluid in the sponge block 9 onto the trapezoidal connecting block 11, and then flowing from the inclined sides of the connecting block 11 to the recovery pipe, and then flowing to the connecting piece 3, thereby improving the sponge block 9's conveying efficiency of the return fluid, and at the same time preventing the amount of return fluid in the recovery pipe from being affected by a large amount of return fluid remaining in the sponge block 9, thereby affecting the accuracy of the measurement result of the pressure sensor 8.

[0054] When the sponge block 9 is squeezed and pushed, the pointed cone 23 will also be pushed upward to push away the soil accumulated on the filter hole 14 for dredging. At the same time, the hollow block 24 will also move upward with the pointed cone 23. During the upward movement of the hollow block 24, its free end will be limited by the limiting rod 25 and stop moving upward. Then the hollow block 24 will be elongated and deformed in the subsequent rising process, and at the same time, it will be squeezed and deformed and expanded by the soil above the filter hole 14, so that the adjacent hollow blocks 24 expand to fit each other and form a seamless and complete conical surface, thereby pushing the soil in the filter hole 14 out and pushing it to the top side of the filter hole 14, thereby effectively dredging the filter hole 14 and preventing the filter hole 14 from being blocked.

[0055] When the guide column 10 squeezes the sponge block 9, the elastic block 15 is also squeezed. At this time, the elastic block 15 will first deform and expand to squeeze the inside of the sponge block 9, thereby further squeezing the return liquid in the sponge block 9. Then, when the sponge block 9 is continuously squeezed, the elastic block 15 will shrink, so that the gas in the elastic block 15 is blown out from the air outlet. At this time, the blown gas can be blown onto the guide column 10 and the connecting block 11, thereby blowing away the return liquid remaining on the guide column 10 and the connecting block 11; at the same time, the gas can also be blown to the top of the sponge block 9 to dredge the top of the sponge block 9, thereby further reducing the blockage of the sponge block 9.

[0056] When there is return fluid on the connecting piece 3, the connecting piece 3 will bend and deform downward. In the later stage when the oil pump is extracting the return fluid in the recovery pipe, since the position of the return fluid in the recovery pipe is relatively low, some of the return fluid cannot be easily extracted. At this time, the connecting block 11 can be pushed with the help of the electric telescopic rod 12, so that the connecting block 11 pulls the connecting line 17. At this time, the connecting line 17 will pull the connecting piece 3, so that the connecting piece 3 bends slightly upward, lifting the position of the return fluid, so that it is more convenient for the oil pump to extract the return fluid in the recovery pipe.

[0057] When multiple recovery pipes are connected, when the connector 2 of one recovery pipe enters into another recovery pipe, the sealing sleeve 18 will fit with the connector 2. At this time, the connecting film 21 can be crushed with the help of a crushing mechanism, so that the glue stored between the sealing sleeve 18 and the inner wall of the recovery pipe flows to the connection part between the connector 2 and the recovery pipe, thereby improving the sealing effect of the connection part between the connector 2 and the recovery pipe.

[0058] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0059] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0060] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A fracturing flowback fluid recovery pipe for oil production, characterized by: The invention comprises a tubular main body (1), the top surface of the main body (1) is provided with a plurality of penetration holes (16), the bottom surface of the inner wall of the main body (1) is fixedly connected with a connecting piece (3), the connecting piece (3) is made of elastic material, the gap between the connecting piece (3) and the bottom surface of the inner wall of the main body (1) forms a first cavity (4), the first cavity (4) is connected with a hollow fixed block (5), the inner wall of the fixed block (5) is sealingly and slidably connected with a slide plate (6), the bottom end of the slide plate (6) is fixedly connected with a spring (7), the end of the spring (7) away from the slide plate (6) is fixedly connected with a pressure sensor (8), the end of the pressure sensor (8) away from the spring (7) is fixedly connected with the bottom surface of the fixed block (5), and the bottom side wall of the fixed block (5) is provided with an air vent.

2. A fracturing flowback fluid recovery pipe for oil production according to claim 1, characterized in that: A sponge block (9) is fixedly connected inside the penetration hole (16).

3. A fracturing flowback fluid recovery pipe for oil production according to claim 2, characterized in that: A guide column (10) is arranged below the sponge block (9).

4. The fracturing flowback fluid recovery pipe for oil production according to claim 3, characterized in that: The inner wall of the main body (1) is fixedly connected with a telescopic mechanism, and a connecting block (11) is fixedly connected to the telescopic mechanism, and the telescopic mechanism is used to drive the connecting block (11) to rise and fall; the bottom end of the guide column (10) is fixedly connected to the connecting block (11), and the top end of the guide column (10) can extend into the penetration hole (16) and squeeze the sponge block (9); the top end of the sponge block (9) is provided with a partition (13), and the partition (13) is fixedly connected to the inner wall of the penetration hole (16), and a plurality of filtering holes (14) are opened on the partition (13).

5. The fracturing flowback fluid recovery pipe for oil production according to claim 4, characterized in that: The sponge block (9) is embedded with a hollow elastic block (15), a plurality of air outlet holes are provided on the elastic block (15), and the elastic block (15) is made of elastic material.

6. The fracturing flowback fluid recovery pipe for oil production according to claim 4, characterized in that: A connecting wire (17) is fixedly connected to the bottom end of the connecting block (11), and one end of the connecting wire (17) away from the connecting block (11) is fixedly connected to the connecting piece (3).

7. The fracturing flowback fluid recovery pipe for oil production according to claim 4, characterized in that: The telescopic mechanism is an electric telescopic rod (12), the top end of which is fixedly connected to the connection block (11); or the telescopic mechanism is a cylinder, the piston rod of which is fixedly connected to the connection block (11).

8. The fracturing flowback fluid recovery pipe for oil production according to claim 4, characterized in that: A pointed cone (23) is fixedly connected to the top of the sponge block (9) at a position corresponding to the filtering hole (14); a group of hollow blocks (24) in the shape of ring-shaped uniform hooks are fixedly connected to the surface of the pointed cone (23); one end of the hollow block (24) away from the pointed cone (23) is a free end; the hollow block (24) is made of elastic material; a limiting rod (25) is fixedly connected to the inner wall of the filtering hole (14); the limiting rod (25) is used to limit the upward movement of the free end of the hollow block (23).

9. The fracturing flowback fluid recovery pipe for oil production according to claim 1, characterized in that: A connection port is provided at one end of the main body (1), and a connection head (2) is provided at the other end; an annular sealing sleeve (18) is fixedly connected to the inner wall of the main body (1) near the connection port, and a gap is provided between the sealing sleeve (18) and the inner wall of the main body (1); the sealing sleeve (18) is fixedly connected to the connecting piece (3) at one side near the fixing block (5), and an annular spacer (19) is fixedly connected between the sealing sleeve (18) and the inner wall of the main body (1), and the sealing sleeve (18) and the spacer (19) are made of elastic material; glue is stored in the gap, and a liquid outlet groove (20) penetrating the sealing sleeve (18) is provided on the surface of the sealing sleeve (18), and a connecting membrane (21) is fixedly connected to the inner wall of the liquid outlet groove (20), and a crushing mechanism is provided on the sealing sleeve (18), and the crushing mechanism includes a chamfer (26) provided on the inner side wall of the sealing sleeve (18).

10. The fracturing flowback fluid recovery pipe for oil production according to claim 9, characterized in that: An annular elastic membrane (22) is fixedly connected between the side of the spacer (19) away from the connecting sheet (3) and the inner wall of the main body (1), and the glue is filled in the cavity between the elastic membrane (22) and the sealing sleeve (18).

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